Managing NOx gas emissions from combustion.

26/09/2019
Pollution can only be managed effectively if it is monitored effectively.

James Clements

As political pressure increases to limit the emissions of the oxides of nitrogen, James Clements, Managing Director of the Signal Group, explains how the latest advances in monitoring technology can help.

Nitrogen and oxygen are the two main components of atmospheric air, but they do not react at ambient temperature. However, in the heat of combustion, such as in a vehicle engine or within an industrial furnace or process, the gases react to form nitrogen oxide (NO) and nitrogen dioxide (NO2). This is an important consideration for the manufacturers of combustion equipment because emissions of these gases (collectively known as NOx) have serious health and environmental effects, and are therefore tightly regulated.

Nitrogen dioxide gas is a major pollutant in ambient air, responsible for large numbers of premature deaths, particularly in urban areas where vehicular emissions accumulate. NO2 also contributes to global warming and in some circumstances can cause acid rain. A wide range of regulations therefore exist to limit NOx emissions from combustion sources ranging from domestic wood burners to cars, and from industrial furnaces and generators to power stations. The developers of engines and furnaces therefore focus attention on the NOx emissions of their designs, and the operators of this equipment are generally required to undertake emissions monitoring to demonstrate regulatory compliance.

The role of monitoring in NOx reduction
NOx emissions can be reduced by:

  • reducing peak combustion temperature
  • reducing residence time at the peak temperature
  • chemical reduction of NOx during the combustion process
  • reducing nitrogen in the combustion process

These primary NOx reduction methods frequently involve extra cost or lower combustion efficiency, so NOx measurements are essential for the optimisation of engine/boiler efficiency. Secondary NOx reduction measures are possible by either chemical reduction or sorption/neutralisation. Naturally, the effects of these measures also require accurate emissions monitoring and control.

Choosing a NOx analyser
In practice, the main methods employed for the measurement of NOx are infrared, chemiluminescence and electrochemical. However, emissions monitoring standards are mostly performance based, so users need to select analysers that are able to demonstrate the required performance specification.

Rack Analyser

Infrared analysers measure the absorption of an emitted infrared light source through a gas sample. In Signal’s PULSAR range, Gas Filter Correlation technology enables the measurement of just the gas or gases of interest, with negligible interference from other gases and water vapour. Alternatively, FTIR enables the simultaneous speciation of many different species, including NO and NO2, but it is costly and in common with other infrared methods, is significantly less sensitive than CLD.

Electrochemical sensors are low cost and generally offer lower levels of performance. Gas diffuses into the sensor where it is oxidised or reduced, which results in a current that is limited by diffusion, so the output from these sensors is proportional to the gas concentration. However, users should take into consideration potential cross-sensitivities, as well as rigorous calibration requirements and limited sensor longevity.

The chemiluminescence detector (CLD) method of measuring NO is based on the use of a controlled amount of Ozone (O3) coming into contact with the sample containing NO inside a light sealed chamber. This chamber has a photomultiplier fitted so that it measures the photons given off by the reaction that takes place between NO and O3.

NO is oxidised by the O3 to become NO2 and photons are released as a part of the reaction. This chemiluminescence only occurs with NO, so in order to measure NO2 it is necessary to first convert it to NO. The NO2 value is added to the NO reading and this is equates to the NOx value.

Most of the oxides of nitrogen coming directly from combustion processes are NO, but much of it is further oxidised to NO2 as the NO mixes with air (which is 20.9% Oxygen). For regulatory monitoring, NO2 is generally the required measurement parameter, but for combustion research and development NOx is the common measurand. Consequently, chemiluminescence is the preferred measurement method for development engineers at manufacturer laboratories working on new technologies to reduce NOx emissions in the combustion of fossil fuels. For regulatory compliance monitoring, NDIR (Non-Dispersive Infrared) is more commonly employed.

Typical applications for CLD analysers therefore include the development and manufacture of gas turbines, large stationary diesel engines, large combustion plant process boilers, domestic gas water heaters and gas-fired factory space heaters, as well as combustion research, catalyst efficiency, NOx reduction, bus engine retrofits, truck NOx selective catalytic reduction development and any other manufacturing process which burns fossil fuels.

These applications require better accuracy than regulatory compliance because savings in the choice of analyser are negligible in comparison with the market benefits of developing engines and furnaces with superior efficiency and better, cleaner emissions.

Signal Group always offers non-heated, non-vacuum CLD analysers for combined cycle gas turbine (CCGT) power stations because these stations emit lower than average NOx levels. NDIR analysers typically have a range of 100ppm whereas CLD analysers are much more sensitive, with a lower range of 10ppm. Combustion processes operating with de-NOX equipment will need this superior level of sensitivity.

There is a high proportion of NO2 in the emissions of CCGT plants because they run with high levels of air in the combustion process, so it is necessary to convert NO2 to NO prior to analysis. Most CLD analysers are supplied with converters, but NDIR analysers are not so these are normally installed separately when NDIR is used.

In the USA, permitted levels for NOx are low, and many plants employ de-NOx equipment, so CLD analysers are often preferred. In Europe, the permitted levels are coming down, but there are fewer CCGT Large Plant operators, and in other markets such as India and China, permitted NOx emissions are significantly higher and NDIR is therefore more commonly employed.

In England, the Environment Agency requires continuous emissions monitors (CEMS) to have a range no more than 2.5 times the permitted NOx level, so as a manufacturer of both CLD and NDIR analysers, this can be a determining factor for Signal Group when deciding which analysers to recommend. The UK has a large number of CCGT power plants in operation and Signal Group has a high number of installed CEMS at these sites, but very few new plants have been built in recent years.

New NOx analysis technology
Signal Group recently announced the launch of the QUASAR Series IV gas analysers which employ CLD for the continuous measurement of NOx, Nitric Oxide, Nitrogen Dioxide or Ammonia in applications such as engine emissions, combustion studies, process monitoring, CEMS and gas production.

Chemiluminescence Analyser

The QUASAR instruments exploit the advantages of heated vacuum chemiluminescence, offering higher sensitivity with minimal quenching effects, and a heated reaction chamber that facilitates the processing of hot, wet sample gases without condensation. Signal’s vacuum technology improves the signal to noise ratio, and a fast response time makes it ideal for real-time reporting applications. However, a non-vacuum version is available for trace NOx measurements such as RDE (Real-world Driving Emissions) on-board vehicle testing, for which a 24VDC version is available.

A key feature of these latest instruments is the communications flexibility – all of the new Series IV instruments are compatible with 3G, 4G, GPRS, Bluetooth, Wifi and satellite communications; each instrument has its own IP address and runs on Windows software. This provides users with simple, secure access to their analyzers at any time, from almost anywhere.

In summary, it is clear that the choice of analyser is dictated by the application, so it is important to discuss this with appropriate suppliers/manufacturers. However, with the latest instruments, Signal’s customers can look forward to monitoring systems that are much more flexible and easier to operate. This will improve NOx reduction measures, and thereby help to protect both human health and the environment.


Directing traffic smartly.

01/09/2019

In the 17th century, Captain Frans Banninck Cocq, the central figure in Rembrandt’s masterpiece `The Night Watch’ (housed at the Rijksmuseum, pictured above) provided safety and security in Amsterdam. Today, the city relies on the Verkeer en Openbare Ruimte to ensure safe navigation through the busy streets. (See reproduction of the famous picture at bottom of this article)

Amsterdam is the largest city in the Netherlands, with a population of 2.4 million. The city is also one of Europe’s leading tourist destinations, attracting around 6 million people a year. Amsterdam’s oldest quarter, the medieval centre, is very small and has an incredibly complex infrastructure, with roads, tunnels, trams, metro, canals and thousands of bicycles. This creates one of the world’s most challenging traffic management environments, which the office for Traffic and Public Space (Verkeer en Openbare Ruimte) meets through vision, action and modern technology. This is typified by the new intelligent data communications network being installed to support the city’s traffic control system, for which they have selected advanced Ethernet switching and routing technology from Westermo.

In 2015, the municipality of Amsterdam created its own team that was responsible for the development and operation of the data communication network that supports the Intelligent Traffic Systems (ITS) in the city. Previously, this was managed by an external partner, but due to rising costs, and increasing performance and cybersecurity requirements, it was decided the best way forward was to take back full responsibility for the network.

Eric Bish, Senior Systems and Management Engineer and Project Manager and Albert Scholten, System and Management Engineer, were two key members of this team responsible for the Information and Communications Technology (ICT) systems for traffic control in Amsterdam.

Albert Scholten

“The existing communications network supporting the traffic control system had served us well for many years, but it had become outdated and the daily costs to maintain the leased line copper network was very high. With the challenges the city faced going forward, we needed to modernise our systems,” said Scholten.

“The old network was mostly based on analogue modems, multi-drop-modems, xDSL extenders and 3G routers from Westermo,” explained Bish. “These devices have proved to be very reliable, so when we started to look at the requirements for the new system, Westermo technology was given serious consideration.”

Project planning
“We worked closely with Axians, our supplier of network services, and Modelec Data Industrie, the distributor of Westermo products in the Netherlands. The collaboration between the three parties was essential to the success of the project. Modelec Data Industrie are very knowledgeable about industrial data communications and during constructive discussions regarding the system requirements they suggested that Westermo technologies would be a good choice for building a robust and reliable network for the future.

“From our meetings a roadmap was established. Our long-term plan is largely based on having a fibre optic infrastructure managed by Westermo Lynx and RedFox Ethernet switches. However, installing new cables is a costly and time-consuming process, so where existing fibre optic cabling is not already available, we have found the Westermo Wolverine Ethernet Extender to be extremely useful. This device allows us to create reliable, high speed, fully managed network solutions using the existing copper cables linking the traffic light systems. For remote connections, between the edge networks and the control centre, we have used Westermo MRD 4G cellular routers, which offer a redundant SIM option and simplifies the process of setting up IPSEC VPN’s.”

Equipment testing

Eric Bish

Before a large-scale implementation of the new system could begin, the Lynx switches and Wolverine Ethernet Extenders were tested at some of the less critical road junctions. To assess the Westermo MRD 4G cellular routers, a mobile test system was constructed and taken to popular parts of Amsterdam during King’s day, the annual Dutch national holiday and busiest day of the year. Despite the huge crowds swamping the mobile masts, the routers delivered excellent performance.

“Having met our required standards during testing, the Westermo devices were deployed extensively throughout the city and are now providing the data communications for several major traffic control systems. Over 1300 pieces of equipment are currently connected via the new network and with the traffic control systems being constantly upgraded this figure continues to grow.”

Westermo offers a broad range of products suitable for traffic control applications, which has helped us to meet all of our needs for this project. We have found the technology to be robust and reliable. The devices consume very low power, which means they generate little heat. This is important, as the switches are often installed in cramped, unventilated cabinets with other electronics that can be damaged if they get too hot.

“The Westermo Lynx switch is very versatile, offering an array of smart features and network connections. For example, the SFP option gave us the ability to easily switch between copper and fiber wiring, while the serial port enabled connection to legacy traffic light systems. The option to perform text-based configuration from a console port has supported our need for fine granular control and rapid mass deployment of devices. Every device received a consistent configuration, but we had the flexibility to adjust the configuration of specific devices, where required. This functionality has enabled us to install all the devices in a little over 12 months. This helped us to make significant savings because the costly leased lines to the datacenter could be terminated sooner.

Network capability
“While we were installing the new network, we needed to retain the old system and move the functionality across gradually. However, with the cost of maintaining the old leased line copper network was so high, we wanted the new network to be very simple and fast to implement. We started with a classic layer-2 approach, consisting of an MRD router and up to six Lynx switches or Line Extenders connected to it. Every Traffic Light Controller was then connected to a Line Extender or switch, depending on the existing cabling in place.

However, because it is difficult, time consuming and costly to install and maintain a data network of this size within a city such as Amsterdam, we knew the new network would eventually have to be able to support more than just the traffic light systems. In fact, it must support camera surveillance, traffic information systems, automatic number plate recognition camera and even public lighting systems. Critically, these other applications must be isolated from each other for security purposes, while changes or additions to the network must also be simple to achieve.

“Efficient use of the cable infrastructure is therefore critical, which is why we selected switches with layer 3 functionality at the start of the project. This enabled us to create a layer-3 network design. A clever combination of OSPF routing, local firewalling and layer-2 and layer-3 features has yielded a very flexible, secure and redundant gateway network design. The network is now sufficiently resilient to withstand common issues, such as cable damage and power outages.

“Using the Westermo Redfox switches, we will soon couple our updated network to the fiber optic rings used to control the city’s metro lines. This will provide fully redundant gigabit connections to our datacenter for many of our surveillance cameras and traffic systems.

“Using Westermo technology we have built a robust and reliable networking solution that will last for a long time. The technology offers the functionality we need to modernise the network and enable us to make quick system upgrades over the lifecycle of the system,” Bish added. “As far as we are aware, this is the most advanced network infrastructure in place in The Netherlands and to date the solution has performed flawlessly. We expect that within five years the industrial network will cover the whole of Amsterdam and its surrounding areas and this will almost completely rely on gigabit fiber links, with only a handful 4G connections still required.”

 

Use case 1: Traffic light control
There are several hundred traffic light systems throughout Amsterdam. These work autonomously, but can also be controlled centrally, which is one of the most critical tasks for the city’s department for traffic and public space. In the event of traffic congestion, traffic control centre operators can manage the flow of traffic and if necessary, reroute traffic to less crowded roads.

The traffic light control systems interconnect several traffic lights. The infrastructure connecting the traffic lights is a mix of existing copper cables and new fibre cables. However, in order to connect a string of traffic lights back to the control room, the city has been relying on leased lines. This solution is not only expensive, costing around EUR 2 million per year, but also does not provide the reliability required for a system of this magnitude. The savings made as a result of replacing the leased lines with the Westermo cellular routers is estimated to cover the cost of the network upgrade project within just three years.

Use case 2: Environmental Zone Enforcement
An environmental zone has been established in the central part of Amsterdam with the aim of decreasing pollution from motor vehicles. Vehicles that are not environmentally friendly are prohibited to enter the `green zone’ and automatic number plate recognition cameras have been installed to ensure that the restriction is followed by motorists. Approximately 80 control points have been established at the entrances to the city to monitor about three million cars every day. Between one and five ANPR cameras automatically read the vehicle registration numbers as they pass the control points. The photos are processed inside the camera, converted into simple text information and sent to the control centre through a secure encrypted IPSec VPN tunnel using the MRD 4G cellular router. The City of Amsterdam plan to participate in the European C-ITS smart traffic project, which will allow real-time traffic optimisation. This will mean that there will be a requirement for more bandwidth and lower latency so in time, the mobile connections will be replaced with a fibre optic network, using for example the Lynx and RedFox switches.

Use case 3: Traffic observation and situation assessment
The Amsterdam traffic is continuously monitored from the control centre to help operators maintain the flow of traffic, reduce congestion and minimise the risk of accidents. Operators make decisions based on the information provided by hundreds of cameras installed across the city. Many of the regular surveillance cameras are connected to the network via Westermo switches. The real-time video feed from the ANPR cameras can also be viewed for traffic controlling purposes. These are connected to the control room using Westermo MRD 4G cellular routers, which provide secure IPSec encrypted VPN tunnels. When traffic congestion occurs, the traffic control managers are permitted to disable the environmental monitoring system and activate predefined scenarios that reroutes the traffic to dissolve the congestion.

De Nachtwacht (The Night Watch)

@westermo @hhc_lewis #Netherlands

Gas sensing in the purification process of drinking water.

28/08/2019

The processing of clean and safe drinking water is an international issue. Estimates suggest that, if no further improvements are made to the availability of safe water sources, over 135 million people will die from potentially preventable diseases by 2020.1

Even within Britain, water purification and treatment is big business, with £2.1 billion (€2.37b 28/8/2019) being invested by utilities in England and Wales between 2013 and 2014.2 Water purification consists of removing undesirable chemicals, bacteria, solids and gases from water, so that it is safe to drink and use. The standard of purified water varies depending on the intended purpose of the water, for example, water used for fine chemical synthesis may need to be ‘cleaner’ i.e. have fewer chemicals present, than is tolerable for drinking water, the most common use of purified water.

Purification Process
The process of water purification involves many different steps. The first step, once the water has been piped to the purification plant, is filtering to remove any large debris and solids. There also needs to be an assessment of how dirty the water is to design the purification strategy. Some pretreatment may also occur using carbon dioxide to change pH levels and clean up the wastewater to some extent. Here, gas monitors are used to ensure the correct gas levels are being added to the water and unsafe levels of the gas do not build up.

The following steps include chemical treatment, an filtration to remove dissolved ionic compounds.3 Then, disinfection can occur to kill any remaining bacteria or viruses, with additional chemicals being added to provide longer lasting protection.4 At all stages, the water quality must be constantly monitored. This is to ensure that any pollutants have been adequately removed and the water is safe for its intended purpose.

In-line gas monitors are often used as part of the water treatment process as a way of monitoring total organic carbon (TOC) content. Carbon content in water can arise from a variety of sources, including bacteria, plastics or sediments that have not been successfully removed by the filtration process.5 TOC is a useful proxy for water cleanliness as it covers contamination from a variety of different sources.

To use non-dispersive infrared (NDIR) gas monitors to analyze the TOC content of water, a few extra chemical reactions and vaporization need to be performed to cause the release of CO2 gas. The resulting concentration of gas can then be used as a proxy of TOC levels.6 This then provides a metric than can be used to determine whether additional purification is required or that the water is safe for use.

Need for Gas Monitors
NDIR gas sensors can be used as both a safety device in the water purification process as carbon dioxide, methane, and carbon monoxide are some of the key gases produced during the treatment process. 5 The other key use is for analysis of TOC content as a way of checking for water purity.7 NDIR sensors are particularly well suited for TOC analysis as carbon dioxide absorbs infrared light very strongly. This means that even very low carbon dioxide concentrations can be detected easily, making it a highly sensitive measurement approach.6 Other hydrocarbon gases can also easily be detected in this way, making NDIR sensors a highly flexible, adaptable approach to monitoring TOC and dissolved gas content in water.

Sensor Solutions
The need for constant gas monitoring to guide and refine the purification process during wastewater treatment means water purification plants need permanent, easy to install sensors that are capable of continual online monitoring. One of the most effective ways of doing this is having OEM sensors that can be integrated into existing water testing equipment to also provide information on water purity.

These reasons are why Edinburgh Sensors range of nondispersive infrared (NDIR) gas sensors are the perfect solution for water purification plants. NDIR sensors are highly robust with excellent sensitivity and accuracy across a range of gas concentrations. Two of the sensors they offer, the Gascard NG8 and the Guardian NG9 are suitable for detecting carbon monoxide, carbon dioxide or other hydrocarbon gases. If just carbon dioxide is of interest, then Edinburgh Sensors offers are more extensive range of monitors, including the Gascheck10 and the IRgaskiT.11

The advantage of NDIR detection for these gases are the device initial warm-up times are less than 1 minute, in the case of the Guardian NG. It is also capable of 0 – 100 % measurements such gases with a response time of less than 30 seconds from the sample inlet. The readout is ± 2 % accurate and all these sensors maintain this accuracy over even challenging environmental conditions of 0 – 95 % humidity, with self-compensating readout.

The Guardian NG comes with its own readout and menu display for ease of use and simply requires a reference gas and power supply to get running. For water purification purposes, the Gascard is particularly popular as the card-based device is easy to integrate into existing water testing equipment so testing of gases can occur while checking purity. .
Edinburgh Sensors also offers custom gas sensing solutions and their full technical support throughout the sales, installation and maintenance process.

References
1. Gleick, P. H. (2002). Dirty Water: Estimated Deaths from Water-Related Diseases 2000-2020 Pacific. Pacific Institute Researc Report, 1–12.

2. Water and Treated Water (2019), https://www.gov.uk/government/publications/water-and-treated-water/water-and-treated-water

3. Pangarkar, B. L., Deshmukh, S. K., Sapkal, V. S., & Sapkal, R. S. (2016). Review of membrane distillation process for water purification. Desalination and Water Treatment, 57(7), 2959–2981. https://doi.org/10.1080/19443994.2014.985728

4. Hijnen, W. A. M., Beerendonk, E. F., & Medema, G. J. (2006). Inactivation credit of UV radiation for viruses, bacteria and protozoan (oo)cysts in water: A review. Water Research, 40(1), 3–22. https://doi.org/10.1016/j.watres.2005.10.030

5. McCarty, P. L., & Smith, D. P. (1986). Anaerobic wastewater treatment. Environmental Science and Technology, 20(12), 1200–1206. https://doi.org/10.1021/es00154a002

6. Scott, J. P., & Ollis, D. F. (1995). Integration of chemical and biological oxidation processes for water treatment: Review and recommendations. Environmental Progress, 14(2), 88–103. https://doi.org/10.1002/ep.670140212

7. Florescu, D., Iordache, A. M., Costinel, D., Horj, E., Ionete, R. E., & Culea, M. (2013). Validation procedure for assessing the total organic carbon in water samples. Romanian Reports of Physics, 58(1–2), 211–219.

8. Gascard NG, (2019), https://edinburghsensors.com/products/oem/gascard-ng/

9. Guardian NG (2019) https://edinburghsensors.com/products/gas-monitors/guardian-ng/

10. Gascheck (2019), https://edinburghsensors.com/products/oem/gascheck/

11. IRgaskiT (2019), https://edinburghsensors.com/products/oem-co2-sensor/irgaskit/

12. Boxed GasCard (2019) https://edinburghsensors.com/products/oem/boxed-gascard/

 

#Pauto @Edinst

Soil carbon flux research!

21/11/2018
Measuring soil carbon flux gives an insight into the health of forest ecosystems and provides feedback on the effects of global warming. This article, from Edinburgh Instruments, outlines how soil CO2 efflux is determined and the applications of soil carbon flux research.

Soil is an important part of the Earth’s carbon cycle.
Pic: pixabay.com/Picography

The Earth’s carbon cycle maintains a steady balance of carbon in the atmosphere that supports plant and animal life. In recent years, concerns about the increasing levels of CO2 in the atmosphere, indicating a problem in Earth’s carbon cycle, has been a prominent global issue.1,2

As a part of a stable carbon cycle, carbon is exchanged between carbon pools including the atmosphere, the ocean, the land and living things in a process known as carbon flux. Carbon exchange typically takes place as a result of a variety of natural processes including respiration, photosynthesis, and decomposition.

Since the industrial age, humans have begun to contribute to carbon exchange with activities such as fuel burning, and chemical processes, which are believed to be responsible for increasing atmospheric CO2 concentrations and increasing global temperatures.1-3

Soil carbon flux provides feedback on environmental conditions
Soil is a vital aspect of the Earth’s carbon cycle, containing almost three times more carbon than the Earth’s atmosphere. Carbon is present in soil as ‘solid organic carbon’ including decomposing plant and animal matter. Over time, microbial decomposition of the organic components of soil releases carbon into the atmosphere as CO2.4,5

The amount of carbon present in soil affects soil fertility, plant growth, microbial activity, and water quality. Studying the carbon flux of soil gives an insight into an ecosystem as a whole and specific information about microbial activity and plant growth.4-6

Soil carbon flux can also help us to understand and predict the effects of global warming. As global temperatures increase, is it expected that microbial activity will also increase, resulting in faster plant decomposition and increased CO2 efflux into the atmosphere.5,6

Measuring soil CO2 efflux
Determining soil-surface CO2 efflux can be challenging. Researchers commonly employ a chamber combined with CO2 concentration measurements to determine CO2 efflux. A variety of chambers have been designed for such research, some of which are commercially available.7-10

Closed-chamber systems typically pump air through a gas analyzer, which measures CO2 concentration, before returning the air to the chamber. Soil CO2 efflux is then estimated from the rate of increase of CO2 concentration in the chamber.

Open-chambers pump ambient air into the chamber and measure the change in CO2concentration between the air entering the chamber and the air leaving the chamber to determine the soil CO2 efflux.

Of the two chamber types, open chambers are considered more accurate. Closed chambers tend to underestimate CO2 efflux as increased CO2 concentrations in the chamber cause less CO2 to diffuse out of the soil while the chamber is in place.10,11.

Often, CO2 concentrations in chambers are measured periodically and then extrapolated to give an estimation of CO2 efflux. This method can be inaccurate because CO2 efflux can vary significantly between measurements with changes in environmental conditions.

A further limitation of using chambers for CO2 efflux measurements is that chambers typically only provide measurements in one location, while CO2 efflux has been found to vary widely even in relatively homogeneous environments. The overall result is CO2 efflux data with limited temporal and spatial resolution, that does not reflect the environmental situation as a whole.10,12,13

Naishen Liang

A group of researchers from the National Institute for Environmental Studies (Japan) led by Naishen Liang has designed an automated, multi-chamber chamber system for measuring soil-surface CO2 efflux.

As CO2 concentrations are measured automatically using an infrared gas sensor, COefflux can be determined accurately throughout the experiment. The improved temporal resolution, combined with increased spatial detail resulting from the use of multiple chambers gives a better overview of how CO2 efflux varies with time, location, and environmental conditions within an ecosystem.10

Liang and his team have applied his method to gather information about a range of forest ecosystems. Their automated chambers have been used in a variety of forest locations combined with heat lamps to provide high-resolution, long-term data about the effects of warming on microbial activity and CO2 efflux.

Liang’s research has shown that soil temperatures have a significant effect on COefflux in a wide range of forest environments, information that is vital for understanding how global warming will affect forest ecosystems and the Earth’s carbon cycle as a whole.14-17

All chamber systems for determining CO2 efflux rely on accurate CO2 concentration analysis. Infrared gas analyzers are the most widely used method of instrumentation for determining CO2 concentrations in soil CO2 efflux measurement chambers.8,10,18

Infrared gas sensors, such as gascard sensors from Edinburgh Sensors, are well suited to providing CO2 concentration measurements in soil chambers, and are the sensors of choice used by Liang and his team.

The gascard sensors are robust, low-maintenance, and easy to use compared with other sensors. They provide rapid easy-to-interpret results and can be supplied as either complete boxed sensors (the Boxed Gascard) or as individual sensors (the Gascard NG) for easy integration into automated chambers.19,20


Notes, References and further reading
1. ‘The Carbon Cycle’
2. ‘Global Carbon Cycle and Climate Change’ — Kondratyev KY, Krapivin VF, Varotsos CA, Springer Science & Business Media, 2003.
3. ‘Land Use and the Carbon Cycle: Advances in Integrated Science, Management, and Policy’ — Brown DG, Robinson DT, French NHF, Reed BC, Cambridge University Press, 2013.
4. ‘Soil organic matter and soil function – Review of the literature and underlying data’ — Murphy BW, Department of Environment and Energy, 2014
5. ‘The whole-soil carbon flux in response to warming’ — Hicks Pries CE, Castanha C, Porras RC, Torn MS, Science, 2017.
6. ‘Temperature-associated increases in the global soil respiration record’ — Bond-Lamberty B, Thomson A, Nature, 2010.
7. ‘Measuring Emissions from Soil and Water’ — Matson PA, Harriss RC, Blackwell Scientific Publications, 1995.
8. ‘Minimize artifacts and biases in chamber-based measurements of soil respiration’ — Davidson EA, Savage K, Verchot LV, Navarro R, Agricultural and Forest Meteorology, 2002.
9. ‘Methods of Soil Analysis: Part 1. Physical Methods, 3rd Edition’ — Dane JH, Topp GC, Soil Science Society of America, 2002.
10. ‘A multichannel automated chamber system for continuous measurement of forest soil CO2 efflux’ — Liang N, Inoue G, Fujinuma Y, Tree Physiology, 2003.
11. ‘A comparion of six methods for measuring soil-surface carbon dioxide fluxes’ — Norman JM, Kucharik CJ, Gower ST, Baldocchi DD, Grill PM, Rayment M, Savage K, Striegl RG, Journal of Geophysical Research, 1997.
12. ‘An automated chamber system for measuring soil respiration’ — McGinn SM, Akinremi OO, McLean HDJ, Ellert B, Canadian Journal of Soil Science, 1998.
13. ‘Temporal and spatial variation of soil CO2 efflux in a Canadian boreal forest’ — Rayment MB, Jarvis PG, Soil Biology & Biochemistry, 2000.
14. ‘High-resolution data on the impact of warming on soil CO2 efflux from an Asian monsoon forest’ — Liang N, Teramoto M, Takagi M, Zeng J, Scientific Data, 2017.
15. ‘Long‐Term Stimulatory Warming Effect on Soil Heterotrophic Respiration in a Cool‐Temperate Broad‐Leaved Deciduous Forest in Northern Japan’ —Teramoto M, Liang N, Ishida S, Zeng J, Journal of Geophysical Research: Biogeoscience, 2018.
16. ‘Sustained large stimulation of soil heterotrophic respiration rate and its temperature sensitivity by soil warming in a cool-temperate forested peatland’ — Aguilos M, Takagi K, Liang N, Watanabe Y, Teramoto M, Goto S, Takahashi Y, Mukai H, Sasa K, Tellus Series B : Chemical and Physical Meteorology, 2013.
17. ‘Liang Automatic Chamber (LAC) Network
18. ‘Interpreting, measuring, and modeling soil respiration’ — Ryan MG, Law BE, Biogeochemistry, 2005.
19. ‘Boxed Gascard’
20. ‘Gascard NG’

@edinsensors #Environment #NIESJp

Power needs for autonomous robots!

20/08/2018
Jonathan Wilkins, marketing director at EU Automation, argues that the way we power six axis robots needs to be reassessed to meet the needs of new applications such as autonomous mobile robots (AMRs).

Since industrial six-axis robots were popularised back in the 1960s, the technology that makes up robots, as well as the way in which we now use robots, has changed considerably.

What was once considered a high-risk sector, where robots were relegated to operating in cells and cages behind no-go zones, has changed to one where robots can now work in collaboration with human workers.

Advances in motor technology, actuation, gearing, proximity sensing and artificial intelligence has resulted in the advent of various robots, such as CoBots, that are portable enough to be desktop mounted, as well as autonomous mobile robots (AMRs) that can move freely around a facility.

These systems are not only capable of delivering high payloads weighing hundreds of kilograms, but are also sensitive enough to sense the presence of a human being at distances ranging from a few millimetres to a few metres. The robot can then respond in under a millisecond to stimuli, such as a person reaching out to guide the robot’s hand, and automatically change its power and force-limiting system to respond accordingly.

Although six-axis robots and CoBots are predominantly mains powered, portable AMR service robots are gaining popularity in sectors as diverse as industrial manufacturing, warehousing, healthcare and even hotels. In these settings, they can operate 24/7, only taking themselves out of action for charging and taken offline by an engineer for essential repairs and maintenance.

In the warehousing sector, for example, the picking and packing process can be manually intensive, with operators walking up and down long aisles picking products from a shelf to fulfil each order. This is a time consuming and inefficient process that adds time to the customer order. Using an autonomous mobile robot in this situation can allow the compact robot to pick up the shelf and move it to the human operator in true “goods-to-man” style.

However, this demanding use-cycle prompts the question: are the batteries that power these robots sufficiently suited to this new environment? To answer this, we need to understand the types of batteries used.

The two most popular types of secondary, rechargeable, battery are sealed lead acid (SLA) and lithium-ion (li-ion). Having been around for nearly 160 years, lead acid technology is capable of delivering high surge currents due to its low impedance. However, this type of battery can be large and heavy, making it impractical for smaller machines.

Alternatively, lithium-ion provides the highest density and delivers the highest energy-to-weight ratio of any battery chemistry, which allows design engineers to use it in even the most compact devices. It also maintains a stable voltage throughout its discharge cycle, resulting in highly efficient, long runtimes.

When choosing robotic systems for their application, it’s important that engineers match the right type of battery to the load. As we increasingly begin to rely on smart factories with high levels of portable and mobile automation, considering the power needs of each device will be vital in delivering long run times with high efficiency.

@euautomation #PAuto #Robotics

Motors that let you know when it’s time for a service.

30/07/2018

Simone Wendler, food and beverage segment manager for ABB’s motors and generators business, explains what to expect from a new generation of wireless motor sensor that offers powerful data collection and analytics in a small package.

Nearly all of the motor technology that we still use today was invented over a period of seventy years from 1820–1890, with the first commutated DC electric motor invented by British scientist William Sturgeon in 1833. Clearly, production processes — and the resultant demands on equipment — have changed since then and there is a lot that modern businesses can do to keep pace with the latest technology. 

William Sturgeon – 1783 – 1850

It is estimated that electric motors (pdf) account for 45 per cent of global electricity demand. That’s not surprising when you consider that they’re used to drive everything from pumps and fans to compressors in industries as varied as industrial, commercial, agricultural and transport. The problem is that increasingly complex food and beverage segments place a demand on motors to run continuously for long periods of time. This can lead to premature failure of the motor if it is not monitored closely.

In situations like this, carrying out traditional motor condition monitoring is an expensive and time consuming process. For most businesses that use low voltage motors, it’s often cheaper to simply run the motor until it fails and then replace it with another one. The consequence is that plants face unexpected downtime, lost production and possible secondary damage to other equipment. However, this approach can lead to spoilage of perishable food and drink items when the motor fails, forcing factory staff to spend precious time cleaning and preparing equipment to return it to operation.

The rise of the Industrial Internet of Things (IIoT) combined with a greater focus on energy efficiency, means that businesses no longer need to run motors until they fail. Instead, new technology opens up opportunities to make a drastic improvement to operations. With IIoT devices, businesses can make use of better big-data analytics and machine-to-machine (M2M) communication to improve energy efficiency and diagnose faults ahead of time. IIoT devices enable enhanced condition monitoring, allowing maintenance engineers to remotely monitor and collect operational trend data to minimize unexpected downtime.

Although this is great for future smart factories, it’s not feasible for plant managers to replace an entire fleet of analog motors today. Although modern, three-phase induction motors are much more efficient, smaller and lighter than motors from 120 years ago, the basic concept has not changed much. This creates a barrier for businesses that want to adopt smart technology but simply don’t have the resources to overhaul entire systems.

To address this problem, ABB has developed the ABB AbilityTM Smart Sensor for low voltage motors. The smart sensor can be retrofitted to many types of existing low voltage motors in minutes. It attaches to the motor frame without wires and uses Bluetooth Low Energy to communicate operational data to a smartphone app, desktop PC or even in encrypted form to the cloud for advanced analytics.

The sensor collects data including: various types of vibration, bearing health, cooling efficiency, airgap eccentricity, rotor winding health, skin temperature, energy consumption, loading, operating hours, number of starts and RPM speed.

The result is that the motor lets the operator know when it’s time for a service. Advanced analytics from the cloud can also provide advice on the status and health of the entire fleet. Data collected by ABB shows that the smart sensor can help users reduce motor downtime by up to 70 per cent, extend the lifetime by as much as 30 per cent and lower energy use by up to 10 per cent, a clear indicator that predictive, rather than reactive, maintenance increases reliability.

So, while we’ve come a long way since the days of William Sturgeon and the first commercial motor, plant managers looking to take the next steps should look closely at smart sensing and condition monitoring to truly embrace the age of IIoT.

@ABBgroupnews #PAuto #IIoT

Secure remote access in manufacturing.

24/07/2018
Jonathan Wilkins, marketing director of obsolete industrial parts supplier EU Automation, discusses secure remote access and the challenges it presents.

Whether you’re working from home, picking up e-mails on the go or away on business, it’s usually possible to remotely access you company’s network. Though easy to implement in many enterprises, complexity and security present hefty barriers to many industrial businesses

Industry 4.0 provides an opportunity for manufacturers to obtain detailed insights on production. Based on data from connected devices, plant managers can spot inefficiencies, reduce costs and minimise downtime. To do this effectively, it is useful to be able to access data and information remotely. However, this can present challenges in keeping operations secure.

Secure remote access is defined as the ability of an organisation’s users to access its non-public computing resources from locations other than the organisation’s facilities. It offers many benefits such as enabling the monitoring of multiple plants without travel or even staffing being necessary. As well as monitoring, maintenance or troubleshooting is possible from afar. According to data collected from experienced support engineers, an estimated 60 to 70 per cent of machine problems require a simple fix, such a software upgrade or minor parameter changes – which can be done remotely.

Remote access reduces the cost and time needed for maintenance and troubleshooting and can reduce downtime. For example, by using predictive analytics, component failures can be predicted in advance and a replacement part ordered from a reliable supplier, such as EU Automation. This streamlines the process for the maintenance technician, flagging an error instantly, even if they are not on site.

The challenges of remote access
There are still significant challenges to remote access of industrial control systems, including security, connectivity and complexity. Traditional remote-access includes virtual private networking (VPN) and remote desktop connection (RDC). These technologies are complex, expensive and lack the flexibility and intelligence manufacturers require.

Additional complexity added by traditional technologies can increase security vulnerabilities. Industrial control systems were not typically designed to be connected, and using a VPN connects the system to the IT network, increasing the attack surface. It also means if a hacker can access one point of the system, it can access it all. This was the case in attacks on the Ukrainian power grid and the US chain, Target.

To overcome these issues, manufacturers require a secure, flexible and scalable approach to managing machines remotely. One option that can achieve this is cloud-based access, which uses a remote gateway, a cloud server and a client software to flexibly access equipment from a remote location. In this way, legacy equipment can be connected to the cloud, so that it can be managed and analysed in real-time.

Most manufacturers find that the benefits of remote access can offer outweigh the investment and operational risks. To counteract them, businesses should put together a security approach to mitigate the additional risks remote access introduces. This often involves incorporating layers of security so that if one section is breached, the entire control system is not vulnerable.

When implementing remote access into an industrial control system, manufacturers must weigh up all available options. It’s crucial to ensure your system is as secure as possible to keep systems safe when accessed remotely, whether the user is working from home, on the go, or away on business.

@euautomation #PAuto #Industrie4